How are teacher expectations related to student achievement? Are students readily influenced by erroneous teacher beliefs? Are some types of students more likely than others to be influenced by teacher expectations? Are the expectations of some types of teachers more likely to be self-fulfilling? What are some of the interpersonal processes by which teacher expectations influence and are influenced by students' achievements and motivation? To address these questions, the proposed research will examine relations among naturally-occurring teacher expectations influence student achievement. Five phases of research involving secondary analysis of data on over 3000 students and 200 teachers in sixth and seventh grade math classes in 12 districts in southeastern Michigan. Phase I will test the following hypotheses: 1) Teacher expectations lead to self- fulfilling prophecies and perceptual biases; 2) Teacher expectations are accurate (hypotheses 1 and 2 are not mutually exclusive); 3) Teacher expectations predict student achievement more because they are accurate than because they lead to self-fulfilling prophecies or perceptual biases. Phase II will test the hypothesis that student motivation mediates the self-fulling effects of teachers' expectations on student achievement. Phase III will address factors moderating (facilitating and inhibiting) teacher expectation effects. It will test hypotheses regarding the extent of self-fulfilling prophecies, perceptual biases, and accuracy among different situations, teachers, and students. Phase IV focuses on the hypothesis that the self-fulfilling effects of teacher expectations accumulate over several years (differences among students that result from self-fulfilling prophecies increase each year). Phase V will address the extent to which teacher expectations for whole classes are self-fulfilling, biasing, and accurate. Thus, the proposed research will address basic issues concerning the social construction of reality in an important practical context-- teacher expectations for students.